Multi-function tools are well known in the art, and typically are designed around a jaw-type tool such as gripping tools (pliers and the like) or cutting tools (scissors, shears, pruning tools, etc). These jaw-type tools may or may not be folded or retracted into the handles of the tool, but utilize both handles for operation. And, a seemingly endless list of additional tools such as screw drivers, knife blades, can openers, cork screws, files, awls, etc. are then designed to be incorporated into the handles so that a wide variety of useful tools can be combined into one compact multi-function tool. It should be noted that “blades” and “tools” may be used interchangeably throughout this disclosure, to refer generally to any of the tools listed above that are attached to only one of the handles, and may include a pair of scissors or other hinged tools that can be extracted out of one handle.
Multi-function tools in which the jaw-type tool does not retract or fold into the handles have a significant disadvantage in the size of the overall tool. In order to comfortably use the tool, and be able to apply any reasonable gripping force in the case of pliers and the like, the handles must be long enough to be gripped by the hand. This makes a non-retractable, non-folding tool too long to fit in a pocket, and uncomfortably long to fit in a sheath and be worn on a belt around the waist of the user. Additionally, in the case of cutting tools (scissors, pruning tools, shears, etc), the sharp edges are also exposed and can inadvertently snag or cut people, clothing, etc., perhaps even without the knowledge of the person carrying the tool.
Multi-function tools that retract the jaw-type tool into the handles, as disclosed in U.S. Pat. No. 5,142,721 of Sessions, et al. overcome the tool length issue described in that when the jaw-type tool is retracted the multi-function tool is short enough to be carried comfortably in a pocket or in a sheath, and offers the user and his surroundings protection from sharp surfaces if the jaw-type tool is designed for cutting. This design of tool has significant limitations as well, however. Some of the noted disadvantages include complexity in construction of the tool, somewhat reduced strength of the jaw-type tool (particularly important in gripping tools such as pliers), and a very confined area for extracting other tools out from the cavities within the handles due to the fact that the handles only open a few degrees about their dependent hinged attachment to the tang end of the jaw-type tool. Finally, this type of tool typically maintains a gap between the two handles when the jaw-type tool is retracted into the handle and all other tools are stored within their respective cavities. This is disadvantageous for storage in a pocket, as it becomes a “trap” for loose change, keys, lint, and any other items that may be simultaneously stored in the pocket, so that when the tool is retrieved from the pocket these items are also removed, and can fall from the tool and potentially be lost.
Multi-function tools that fold the jaw-type tool into the handles for storage as disclosed in U.S. Pat. No. 5,743,582 of Rivera overcome the problems associated with both other types of tools previously described, but present a different limitation in that when the jaw-type tool is extended, the handles cannot open the jaw-type tool if any significant force is exerted on the outside of the jaws, as the handles of the tool will start to collapse for storage. This is not particularly significant for cutting tools, but may be a constraint for gripping tools if they are to be used for expanding springs and the like.
One limitation that may be associated with any of these three types of tools is that each of the handles is typically manufactured from a single piece of metal, and is formed generally into a channel shape. And, although this can add structural strength, it becomes significantly more difficult to manufacture the tools with little or no lateral clearance or sideways “play” so that an extended blade or tool is held firmly when encountering forces that act perpendicular to the longitudinal plane, i.e. acting against the side of tool, because of the one-piece construction. The walls of the handle cannot be brought closer together to take up any clearance or “play” without bending the channel itself. Any excess clearance also affects the feel of the tool, potentially giving the user a less than optimal confidence in the tool. Consequently, the thickness of the tools and any interspersed spacers must be precise both individually and cumulatively so as to precisely fill the space between the channel walls.
Another limitation generally associated with any of these types of tools, and with folding knives in general, resides in the blade lock mechanism. Known locking mechanisms used to lock tools in the fully extended position, of which there are many designs, always have a substantial amount of material and numerous parts (lock, spring, and connecting parts) located within the typical storage cavity of the tool handle. In other words, most or all of the blade lock mechanism is contained between the two pivot pins located at the two opposite ends of the tool handle, and generally between the outer side walls of the tool handle. This increases the overall size of the tool, which is undesirable.
It is also desired to avoid clumping, the phenomenon of when one blade is selected for extension, the other tools nearby rotate with the selected tool due to frictional forces holding the tools and interspersed spacers together within the channel of the handle.
Accordingly, there is a need in the art for a multi-function tool that can take advantage of the benefits of the folding type tool, but which can also overcome the noted limitations associated with opening the jaws of previously available tools under force. A need also exists for a handle that provides a greater dimensional tolerance range of the tools in a multi-function tool yet still provides a solid feeling tool that minimizes the amount of lateral “play” associated with the tool, and that facilitates optimal ways of assembling such a tool. A need for removing most or all of the blade locking mechanism from between the two pivot pins of a tool handle yet still providing a secure blade lock mechanism also exists. It is to these ends that the folding multi-function tool of the present invention is primarily directed.